HESPERIOIDEA OF AMERICA 9 



regard to the vexed question of the generic importance of male 

 secondary sexual characters, the conclusion which has been 

 forced upon me is that, in any particular genus in which male 

 secondary sexual characters are found, the particular male char- 

 acter (be it costal fold, discal stigma, or tuft of hairs) may be 

 either present or absent in different species of that same genus, 

 but is never replaced by a character of different structure." 

 This seems by far the most satisfactory attitude to adopt, 

 though it is necessary to understand that in cases such as 

 Thanaos and Hesperia two or three such characters may be pres- 

 ent or absent in various combinations in the several species. In 

 my work, rather than carry the splitting of genera further, I 

 have unhesitatingly followed Watson's conclusion. This has re- 

 sulted in the dropping of a number of familiar genera, but I 

 think that once we are accustomed to the change it will render 

 our classification more convenient and more useful, as well as 

 more natural. Some change is demanded for the sake of con- 

 sistency, and since our genera have already been carried beyond 

 the point of usefulness, "lumping" is the only desirable change. 

 The structures of systematic value in the Hesperioidea are 

 found in all parts of the body. The size of the head serves to 

 distinguish the two families, and its appendages, the palpi and 

 antennae, offer a means of separating many genera. The palpi 

 vary in length and position and the relative size of the second 

 and third joints is useful, but it is necessary to look at all of 

 these things in a general way. For example, in Pholisora as 

 here treated we find great variation in the vestiture of the palpi 

 and in the relative length of the third joint, but throughout the 

 genus long palpi with smooth deep scaly vestiture, an oblique 

 second joint and a porrect third joint with long scales are pres- 

 ent. Thanaos has palpi of a similar form but with shaggy vesti- 

 ture. The third joint in some genera is long, slender and ver- 

 tical. 



The antennae have a characteristic slender tip which has been 

 aptly termed the apiculus. This varies from the tiny point 

 found in Pamphila to the long one of Goniurm, and has been 

 entirely lost in some genera. This modification has apparently 

 taken place by two distinct lines of evolution, first the loss of the 

 apiculus by gradual reduction and second by the thickening and 



